Tie pandan leaf into a knot. Add coconut milk and water into a pot. Add knotted pandan leaf and bring the mixture to a boil over medium heat. Meanwhile, peel the bananas and cut them into four pieces each (quarter halves). Once coconut milk begins boiling, add bananas. Cook until bananas are softer. They should absorb some coconut milk during the cooking process. Finally, add coconut sugar, white sugar and salt. Stir carefully until well combined. Continue boiling for another 5 minutes over medium heat. Serve hot, at room temperature or chilled.